tonight, pentagon sources are telling nbc news syria is preparing chemical weapons for their possible use against the syrian people in the form of aerial bombs. it is believed this specific intelligence is the reason why president obama took a hard line against syria just a few days ago, warning them there would be consequences if these weapons were used. let's begin here tonight with the very latest. >> reporter: good evening, brian, u.s. officials tell us that the syrian military is poised tonight to use chemical weapons against its own people. and all it would take is the final order from syrian president assad. as the fighting grows more intense and syrian rebels close in on damascus, the syrian regime has turned very desperate. u.s. officials tell nbc news the syrian military has now loaded the pre cursor for bombs, that could be dropped from dozens of fighter bombers. this week, u.s. intelligence detected a flurry of activity here, near homes. today, while u.s. officials confirm the precursor chemicals are loaded, they must still be mixed together to create the deadly gas. the a